CN100423902C - electric pressing tool - Google Patents

Abstract

For operational reasons, it is desirable to construct the electric press tool as compact as possible. The pressing tool (1) comprises a hydraulic pump (3) acting on a piston cylinder part (4); a plurality of pliers (2) are locked by the piston-cylinder part, and can be actuated by a roller clamper (7) with a plurality of rollers (8). During actuation, hydraulic oil is discharged from the elastic hydraulic oil container (6) and into the cylinder space (12); and flows back from the cylinder space after pressurization. In order to save space, the invention provides the hydraulic oil reservoir (6) in the form of a sleeve (36) which serves as a cylinder housing (13) for the piston cylinder part (4). An actuating valve (9) located within the piston cylinder part (4) can be actuated while passing through the sleeve (36).

Description

electric pressing tool

technical field

The invention relates to an electric pressing tool with a hydraulic pump acting on a hydraulic piston-cylinder part actuatingly connected to a roller holder, the plurality of rollers of which rolls on the jaws of the pliers to move the rollers relative to each other; the electric pressing tool has a hydraulic oil carrying container and an actuation valve for opening the hydraulic oil carrying container and the Passage between the cylinder spaces of the piston-cylinder part from the advance pipe to the return pipe.

Background technique

Electric pressing tools have been on the market for many years. The first types of hand-held hydraulic impact pressing tools were used to press jointed elements such as sockets, fittings, pipe muffs, partially inter-inserted tubes, and the like. The pressing tool comprises a pliers with a plurality of jaws forming a pressing space that accommodates the connecting element to be pressed. The pressure required for pressing is provided by a general hydraulic drive. The pressing devices commercially available today are relatively large and relatively heavy. Due to the hitherto requirements related to the shape of the structure, structural size reduction has not been successful until now. Dimensional variations of press clamps limit their field of application and, based on this, it is not possible to reduce the size of the clamps according to current knowledge. The corresponding ball holder must also be adapted in size to the clamp; and, of course, this also applies to the fork-like container in which the clamp is fixed and the fork-shaped container is usually Manufactured together with the subsequent cylinder housing as a single component. The size of the cylinder housing actually depends on the concentrated forces, and these forces in turn depend on the size of the clamp. A conduit block arranged behind the cylinder housing is manufactured together with the cylinder housing as one part, the conduit block enabling communication between the cylinder space and the subsequent hydraulic pump. Finally, an electric drive and, for example, a battery powering the electric motor are located after the hydraulic pump.

The required hydraulic oil is sucked from the hydraulic oil container and pumped into the cylinder. At this point, the piston is displaced in the actuation direction and the jaws are closed. Once this clamping process is complete, the hydraulic oil is then pumped back into the hydraulic oil reservoir by means of a number of means, and by means of some means of this type the flow of hydraulic oil from the advance or suction line to the return line is effected by means of a suitably actuated valve direct reflow. The functions described above necessitate the device structure described. Therefore, it is practically impossible to achieve miniaturization without reducing performance. As a result, size reduction of the clamping device can only be achieved through innovative methods.

Contents of the invention

It is therefore the object of the present invention to design a press clamp arrangement of the initially mentioned type in such a way that the overall construction can be reduced. This object is achieved by a press clamp device of the initially stated type having the features of claim 1 . Thereby, the volume of the device is reduced by the space of the separately combined hydraulic oil supply container, and thus the whole device and the housing of the device are also reduced accordingly.

The solution according to the invention can also be realized by means of a press clamp, wherein by means of a manually actuatable actuation valve a return flow of the hydraulic oil from the advance pipe directly into the oil supply space via the return pipe is achieved. To this end, according to the invention, the actuating valve is connected such that it is completely covered by an elastic sleeve in the piston cylinder and the actuation of the valve is effected by pressure acting on the elastic sleeve. With this arrangement, the piston cylinder arrangement can be constructed smaller than previously manufactured arrangements.

Further preferred embodiments of the subject matter of the invention will emerge from the further dependent claims, and the significance and method of operation of said preferred embodiments will be described in the following description with reference to the accompanying drawings. An example of a preferred embodiment of the subject matter of the invention will be given and illustrated in more detail in the accompanying drawings.

Description of drawings

Figure 1 is a perspective view of a possible embodiment of a pressing tool arrangement;

Fig. 2 is a cross-sectional view of a functional part of a pressing tool device according to the prior art;

Fig. 3 is the view of the functional part designed according to the present invention;

Fig. 4 is the view that according to the same functional part shown in Fig. 3 is rotated 90 degrees, and this view is partially cut away;

Fig. 5 only shows the longitudinal sectional view of the piston cylinder omitting the elastic sleeve according to the present invention; and

FIG. 6 is a view of the same components but rotated by 90 degrees, wherein the region of interest is shown here in partial section.

Wherein, the reference signs are explained as follows:

0 Housing of the device 1 Pressing tool

2 Clamps 3 Hydraulic pump

4 Piston Cylinder Parts 5 Gripper Jaws

6 Hydraulic Oil Carrying Container 7 Roller Gripper

8 Roller 9 Actuation valve

10 Advance pipe 10′ Suction pipe

11 return pipe 11′ separation part

12 Cylinder Space 13 Cylinder Housing

14 drive motor 15 piston

16 Return spring 17 Piston closure

18 Cylinder head thread 20 Bearing receiver

21, 22 Large gear 23 Drive shaft

24 Bearing head 25 Seal

26 Pressure ring 27 Circlip

28 Bolt 29 Pump housing

30 Connecting Nut 31 First Locking Groove

32 Annular chamber 33 Annular groove with increased volume

34 Ring Bead 35 Second Locking Groove

36 Elastic Sleeve 37 Clamping Clip

40 Actuation Plunger 41 Bearing Journal

42 Spring 43 Oil filter

44 Actuation Button 45, 46 Sensor Drilling

Detailed ways

An embodiment of a pressing tool arrangement according to the invention is given in the form to be placed on the market. Its actual functional part is also encapsulated by a plastic case. It can further be seen that the clamp 2 has two clamping jaws 5 which are fastened to the fork-shaped receptacle by means of fastening screws. A plurality of rollers 8 are located in the fork receptacle and are rotatably mounted in the roller holder 7 . The rollers 8 are pushed forward by the piston-cylinder part, where the jaws 5 are closed. Figure 5 shows the jaws 5 in a closed state.

For a better understanding of the present invention, the functional parts of a pressing tool device according to the prior art known from European patent EP-A-1157786 are shown with reference to FIG. 2 and briefly described to make the present invention clearer. This functional part includes a hydraulic pump 3 , shown here as a gearwheel pump. The hydraulic pump 3 sucks hydraulic oil out of the elastic hydraulic oil carrying container 6 through the suction pipe 11 and into the cylinder space 12 through the advance pipe 10, while the hydraulic oil pushes the piston 15 forward. At the same time, the roller holder 7 containing the roller 8 is pushed forward via the piston rod, where the roller 8 carried on the jaw 5 is pushed outwards, so that Clamp 2 is closed.

When this pressing process is over, the drive motor 14 is at rest and the hydraulic pump 3 is no longer in operation. By actuating the actuating valve 9 , communication is then established between the forward line 10 and the return line 11 , and the hydraulic oil flowing into the cylinder space 12 is then returned to the elastic hydraulic oil-carrying container 6 . During this process, the return spring 16 pushes the piston 15 back to the initial position, and the hydraulic oil flows through the above-mentioned path via the actuating valve 9 into the elastic hydraulic oil carrying container 6 . With this design, the hydraulic oil-carrying container 6 is located below the piston cylinder 4 in the housing 0 of the pressing tool device 1 . This arrangement enlarges the housing 0 as a whole and thus also the pressing tool device 1 as a whole. The solution according to the invention provides a rather space-saving variant which simplifies the associated manufacturing technology.

The functional part shown in FIG. 2 is shown again in FIG. 3 , but with a design according to the invention. In the embodiment shown, the piston rod connected to the functional part, in particular the roller holder 7 and the plurality of rollers 8 housed in the functional part, have been omitted. The piston 15 has a piston seal 17 and is provided on the end side of the cylinder housing 13 with a thread 18 for fastening the cylinder head. The cylinder housing 13 is connected in one piece with the piston-cylinder part 4 . At that end of the piston-cylinder part 4 opposite the cylinder space 12 there is a bearing receptacle 20 in which the profile of the hydraulic pump is mounted in a fastened manner. Bearings for the bull gears 21 and 22 are formed into the end walls of the piston-cylinder part 4 in a similar manner. A shaft 23 is integrally formed on the bull gear 22 of the bull gear pump 3 and is connected to the drive motor 14 (not shown here). This profile part of the piston pump 3 , said bull gears 21 and 22 and the drive shaft 23 are all installed in a bearing head 24 . The drive shaft 23 is isolated from the outside by a seal 25 and fixed at this position by a pressure ring 26 and a snap ring 27 . As shown in the partial cross-section of FIG. 4 , the pump housing 29 is fastened to the piston cylinder part 4 and the bearing head 24 by bolts 28 .

The connecting nut 30 pushes the bearing head 24 and the hydraulic pump 3 and is screwed on the piston cylinder part 4 .

The largest diameter portion of the piston-cylinder part 4 is directly connected to the coupling nut 30 and approximately corresponds to the diameter of the coupling nut 30 . In this region, the piston-cylinder part 4 includes a first locking groove 31 . Subsequently, the diameter of the piston-cylinder part is reduced and an annular chamber 32 is formed. The volume of the annular chamber 32 is additionally enlarged by the annular groove 33 . In the area where the cylinder housing 13 is connected with the annular chamber 32, an annular bead (annular bead) 34 is integrally formed on the cylinder housing, wherein the diameter surrounded by the annular bead is also the same as that of the first locking groove. Corresponds to the diameter of the piston cylinder in the area. The second locking groove 35 is formed in the annular bead 34 . The sleeve 36 preferably made of rubber elastic material covers the entire area between the first locking groove 31 and the second locking groove 35 . The elastic sleeve 36 thus forms the hydraulic oil carrying container 6 . The elastic sleeve is fixed on the piston cylinder through positive fit and friction fit. To this end, the elastic sleeve 36 comprises suitable beads located in the first locking groove 31 and in the second locking groove 35 . Clamping clips 37 are arranged above the elastic sleeve 36 and can be achieved, for example, by a cable binder to ensure a non-positive connection. In the area covered by the elastic sleeve 36 , preferably in the area of the annular groove 33 provided for increased volume, the piston-cylinder part 4 is traversed by the actuating valve 9 . The actuating valve 9 is perpendicular to the section plane of FIG. 3 .

The same actuating valve from Figure 3 is also shown in Figure 4, but rotated 90 degrees and only partially cut away. The first partial section is used to represent the situation of fastening the hydraulic pump, while the second partial section relates to the travel area of the actuating valve 9 . Likewise, reference is made to European patent EP-A-1157786 regarding the function and construction of the actuating valve 9 . The actuating valve 9 creates or blocks communication between the forward line 10 and the return line 11 depending on the switching conditions. A manually actuated actuation valve 9 can be realized via an actuation plunger 40 passing through a bearing journal 41 . A spring 42 is accommodated in the bearing journal 41 and acts on the actuating plunger 40 and presses the actuating plunger 40 outwards against the inner wall of the elastic sleeve 36 . An actuating button 44 is located in the housing 0 of the pressing tool device 1 and it can be actuatingly connected axially flush with the actuating plunger 40 . In this way, leakage problems of the seal of the hydraulic oil carrying container 6 can be avoided.

At the same time, an oil filter 43 is arranged between the actuating valve 9 and the bearing journal 41 . The oil filter 43 can be produced from sintered metal or plastic particles with a suitably chosen pore size. The oil filter 43 is passed through by the actuating plunger 40 and sealed off from the outside by a sealing ring 45 .

Finally FIGS. 5 and 6 show the piston-cylinder part 4 , wherein the actuating valves are not shown. Here, on the one hand a bore extends straight from the region of the pump into the cylinder space 12 , wherein the bore represents the advance pipe 10 and passes transversely through the accommodating bore of the actuating valve. The second bore is parallel to the first bore forming the advance duct 10 and extends from the pump connection side along into the transverse bore housing the actuating valve 9 . The transverse borehole is subdivided into two parts by the second borehole which is open to the transverse bore. The actual return line 11 runs from the valve bore as far as the opening of the second bore, whereupon a separation 11' is formed at an angle of about 45°, which can be simultaneously As suction and return lines. The separating portion 11' running in an oblique manner is preferably open to an annular groove 33 for increasing said volume. The annular groove 33 has a circular cross-section, and preferably, the separation portion 11 ′ of the return pipe 11 is open to the annular groove 33 . This is advantageous because returning hydraulic oil has been shown to have a lot of energy and its return can damage the sleeve. Therefore, to avoid this from happening, three measures are used. In the first measure, the separation part 11' of the return pipe 11 is connected in an oblique manner, so that the return flow does not cause a vertical impact on the sleeve; the second measure is arranged on one side of the annular groove 33 that increases the volume and separates Portion 11' opens into the annular groove, thereby increasing the distance from the outlet of return pipe 11 to the sleeve. Last but not least, the cross-section of the separation part 11 ′ is larger than the cross-section of the actual return pipe 11 . Thereby, the separation part 11' simultaneously forms an expansion space. The bores 45 and 46 which are additionally present in the piston cylinder 4 run perpendicular to the longitudinal axis and open into the advance pipe 10 or the suction pipe 10'. These bores are used to connect sensors that determine the current oil pressure value during pressurization or decompression. A variety of information can be derived from these measurements and will not be discussed in detail here. It is only to be noted that the permeability of the oil filter 43 can be monitored by these measured indicators to identify whether the oil filter needs to be replaced.

Claims (9)

1. electrically operated pressing tool (1) with hydraulic pump (3), this hydraulic pump acts on hydraulic piston cylinder part (4), this hydraulic piston cylinder part is connected with roller clamper (7) with activating, a plurality of rollers of roller clamper are gone up at a plurality of jaws (5) of clamp (2) and are rolled so that described roller moves relative to each other, wherein this operated pressing tool (1) has elasticity hydraulic oil carrying container (6) and activated valve (9), and this activated valve is used for opening the past inlet pipe (10) between this cylinder spaces (12) of this hydraulic oil carrying container (6) and these piston-cylinder parts to the passage of return duct (11); Wherein, this hydraulic oil carrying container (6) is formed by resilient sleeve (36), this resilient sleeve surrounds the cylinder shell (13) of piston-cylinder parts (4) to small part with sealing means, it is characterized in that this activated valve (9) in these piston-cylinder parts (4) is all covered by this resilient sleeve (36) and the actuating of this activated valve is finished by the pressure that affacts on this resilient sleeve.

2. the electrically operated pressing tool with hydraulic pump according to claim 1, it is characterized in that, this operated pressing tool (1) comprises housing (0), in this housing, be equipped with these piston-cylinder parts (4) of part, pump (3) and motor driver (14), and this housing covers this resilient sleeve (36) fully, actuation button (44) wherein is installed in this housing (0), and this actuation button is pressed on this resilient sleeve (36) of this activated valve (9) top when activating.

3. the electrically operated pressing tool with hydraulic pump according to claim 2 is characterized in that, this activated valve (9) is connected in actuating plunger with activating, and the spring pressure in this actuating plunger is supported on the inwall of this resilient sleeve (36) this actuating plunger.

4. the electrically operated pressing tool with hydraulic pump according to claim 3 is characterized in that, is provided with oil screen (43) in this activated valve (9) is passed the zone of this preceding inlet pipe, and this actuating plunger passes this oil screen.

5. the electrically operated pressing tool with hydraulic pump according to claim 1, it is characterized in that, the part of this return duct (11) also is the part of suction tube (10 ') simultaneously, wherein the same return duct that tilts to advance as the longitudinal axis with this cylinder shell (13) of this part of this suction tube.

6. the electrically operated pressing tool with hydraulic pump according to claim 5 is characterized in that, inwardly is formed with the cannelure (33) that is used to increase volume in the zone of this cylinder shell (13) that is covered by this resilient sleeve (36).

7. the electrically operated pressing tool with hydraulic pump according to claim 6 is characterized in that, this return duct (11) of advancing in the inclination mode advances in this cannelure (33).

8. the electrically operated pressing tool with hydraulic pump according to claim 1 is characterized in that, this cylinder shell (13) comprises two annular recess (31), and described annular recess each interval is this resilient sleeve length; This resilient sleeve is provided with and seals the ring around (34) that is installed in the described annular recess (31).

9. the electrically operated pressing tool with hydraulic pump according to claim 8 is characterized in that, described ring around (34) is securely fixed in the described annular recess (31) by the rope band.

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